Question: Simplify the following expression: $2\sqrt{117}$.
Explanation: First, try to factor a perfect square out of the radical. $= 2\sqrt{117}$ $= 2\sqrt{9 \cdot 13}$ Separate the radical and simplify. $= 2\sqrt{9} \cdot \sqrt{13}$ $= 2 \cdot 3 \cdot \sqrt{13}$ $= 6\sqrt{13}$